Blade, they make a good bait just for carpenter ants. Word is in the pest control industry that it works real well. You might try searching for pest control. There are some sites like doit yourself pc that sell to the public. If you can't find it, let me know and I'll see if I can help.

We have a little cabin that I use for canning, storing squash etc. and it was infested with the ants. There were droppings, sawdust etc. dropping down from behind the insulation in the ceiling. I tried commercial baits, bombing several times and no luck. One day I was making citron jam in a crockpot and those ants were commiting suicide falling into the hot jam to get at it. I had tried borax and sugar and they never touched it but I put borax in some of that jam and they ate it like crazy. First there were dozens at a time eating and then they slowed down and now there is none at the jam site. I put it in a jar lid. We were ready to either tear down the insulation or get a professional in so are real happy that this worked. At least for us. Not sure if any jam would work. Good luck. Rita in TN

Blade, I doubt you'll find diazinon or dursban unless you find someplace that has had it a long time. They have been removed from the market. The trouble with borax is getting it in the walls. Requires a lot of hole drilling which leaves you holes to patch or cover up. Then you need a duster of some sort to inject it into the holes and some of those can be pricey. There are a couple cheap ones out there if you look around. Generally the bulb dusters are the least expensive. I use baits whenever possible because they are effective and usually less work to apply.

I remember when I was young, we had the same problem. We couldn't figure out where they were nesting or coming from. It turned out they had eaten their way into our kitchen door and literally made it hollow. With all the sweeping we did, no one noticed. So look for holes in the bottoms and tops of your doors and then slam em with whatever ya got.

As Rita posted, ant bait is sometimes not effective to stopping ants, and will not kill carpenter ants. They require their own bait. Made especially for carpenter ants. They are kind of an odd critter.

I just saw a case where the ants climbed the wall and ate out the entire roof structure. They can do just about anything. The ants live in the wood of the house but they still have to go out to eat. They don't actually "eat" the wood but just dig through it as a living space. Make certain that you find their home and remove it, and I would hestitate to fill my walls with poison.

Serveral years ago, I had a huge problem with carpenter ants. They were al over in the yard and all over in my house. They were nesting in an 80ft tall cottonwood tree in my front yard. I bought some spray and sprayed the trunk of the tree, as high as I could reach, the surrounding ground and the enire foundation of my house. It held them off for about 3 months. The tree was between the sidewalk and the street, so it was considered city property. After 5 years of pleading with the city, they finally cut it down. According to the tree service, they had never attempted to cut down a tree as large as this one. The tree was completely hollowed out from top to bottom, but when the trunk fell it blew a 4ft wide and 4ft deep hole in my front yard and took out 2 sidewalks. As soon as they finished, I paniced because now the ants no longer had a home and I din't want them picking my house as their new one. So I bought some more of the spray and sprayed the heck out of the area where the tree had stood, the front yard from the tree to the house, the foundation and the 200 year old oak tree in the back yard(as a precautionary measure). Haven't seen any since then, but you have got to find the nest and deal with it from there.

A carpenter ant colony can be huge, like 3 million workers or more. Their territory can exceed 5 acres. A mature colony will have a central colony and perhaps several satellite colonies. The main nest would be as big as the your torso. Rotted stumps, fallen trees, or landscape timbers are possible sites. They typically forage for food after dark.

The first concern would be whether there is an active nest in your structure. You can usually get a good idea by inspecting the the exterior of the building. Since they establish trails, you will find a great deal of ant activity on these trails - constant, almost frantic comings and goings. When you see ants carrying their food into your house, it means they live with you. Sometimes the trail can be aerial, across electric lines or trees touching the house. Finding a few ants inside may not be an indication of nesting activity in the structure.

Before development of good baits, it was necessary to locate the nest and destroy it. This required finding the trails and following the ants home. All ants have changes in food needs that will determine whether/when they take the bait. A bait that works today, may not work tomorrow. Carpenter ants are picky. But if they take the bait it will definitely kill the nest.

A nest in the structure is a clue to possible water damage. This could be a roof leak, or water entering through a window flashing, etc. In many cases, if you detect where the water damage is, open it up and remove/replace the damaged wood, the ants will leave on their own. Of course, I would have something in hand to spray the nest when you do the demolition.

Rita's story illustrates a good point. If you find something they like eating, it can be used as the bait. Boric acid is a good toxicant to make your own. The secret is to not overdose it. Because carpenter ant colonies are so huge, the poison must work slowly so every ant gets some. If it is too concentrated, some ants will die, but the survivors will stop eating it.

Keep the boric acid to less than 5% by weight. This can be tricky. An ounce is 28 gms so, 5 percent or less is 1.4 gms or less. If you cannot weigh this small amount, you can make extra bait. A few ounces is more than enough bait if the ants take it.

When I use a commercial bait, I always like to test it before I waste it. They are not cheap. To do this, I locate an active trail and put a small amount right next to the trail (carpenter ants don't like it on the trail!); a few grains or drops is all. I usually sit next to the trail and watch for a bit. Sometimes, they will take it instantly. This is good, add a teaspoon more real close to the trail. Carpenter ants do not always instantly react. If they don't take it instantly, I move on looking for where the trails lead and for other trails. I return to my test spots in 15 minutes or so. If they haven't taken the bait by then, it would be a waste to put any more out.

Poppy is correct about finding dursban or diazanon. They never worked well on ants anyway. Spraying is not effective for ants unless you get it right on the queen and larvae. Poppy is also correct about boric acid in the walls. Its a lot of work for marginal results. It may not work at all.

Carpenter ants can do significant structural damage to your house. I advise you to spend time pondering and inspecting why they are in your house. Seeing a few occasionally may be a sign a nest is somewhere nearby. Seeing a few on a regular basis inside is a cause for alarm. Seeing them inside after the weather changes means the nest is inside. Roof inspectors commonly have moisture meters that help them trace leaks. This tool can also help locate the ant colony.

When it comes to carpenter ant baits on the market, there are several now. What really matters is whether your ants take the bait. If you look on just about any pesticide container, there is a good chance it could say carpenter ants in the detail. This doesn't mean it works well, though. "Carpenter Ants" in the product name is better, but it still won't be a guarantee your ants will take it. I prefer baits light in color only because it is easier to watch for acceptance.

Your best control options for carpenter ants are still finding the nest. Why? "Gobug" is right - carpenter ants are often found where there has been water damage to a home. The ants are a symptom of something that has already happened to the house. They can not have a successful colony without the right conditions - which includes "moisture"/"humidity

If you don't look for the nest location, you still have a structural problem that goes untreated...and another carpenter ant colony can take advantage of the same location.

Although there have been improvements, Carpenter ants still do not take baits well. Their diet is far too varied. Reminder - they don't eat wood. Carpenter ants also don't trail as reliably as "sweet ants"...so while some may be on the bait, others will be foraging in other locations and not impacted by the bait. Long, slow process.

Insecticides also have to be targeted. Foundation/baseboard treatments are not effective. If you apply an insecticide too far from the nest, you won't impact the colony. Insecticide dusts are best and you have to know where the nest is at.

Colonies can sometimes be eliminated by discarding infested wood or by vacuuming ants. In these situations, no insecticides may be needed. Your best choice for control is finding the nest and treating directly, if needed. You will end up needing to make repairs anyway.

Wayuuuulllllll...........We had the hurricanes last year, lots of wet. Also had a hole in the roof, so yeah its probably wet in spots still. The ants were coming out of some flashing holes on either side of the window sill. DW sprayed them, (I know, bad idea) and more came popping out. We live between two orange groves, so the colony could be anywhere. We'll try some Carpenter ant bait and put Boric acid in the holes. Cross your fingers folks.

Bladesmith - your "dusts" - even Boric acid has to stay dry. Carpenter ants are very hairy under a microscope so they are perfect for dust treatments

...but the dust has to stick to them so they can track it around. Hopefully, your "leaky" spot is dry enough the dust won't get "pasty".

I had one situation where a porch roof was leaking badly enough that no amount of dust insecticide would have been helpful. Had to spend $2000 on a new roof for the porch....but amazing, carpenter ants found, wet conditions corrected, dry roof, no ants...no insecticides used!

In our exterminating business, we tried every kind of chemical and formulation to kill ants and still had the most callbacks for ants. When good ant baits became available, our callback rate on ants dropped from nearly 20% to less than 1%. I never had a single call back to treat carpenter ants after I started baiting.

I do not like dusts because they pose the greatest risk to safety. They are the most difficult to handle, and the most toxic of any formulation. Consider boric acid. This is fairly low risk, but a boric acid based bait with 5% concentration and no risk of inhalation is far safer. Dusts almost always should be applied while wearing a good quality respirator, and possibly a full face mask if applied in a confined area. Baits are so much simpler and so much safer.

Contact poisons don't work well, unless you open the nest and get it right on those workers/larvae/queens inside. Only 5% of the ants in colony leave to forage for food. The rest have inside jobs. Since they follow trails, contact poisons kill some, but is eventually worn away by the ants. And the factory keeps making more.

Insecticide dusts do work - and they are still more effective than baits (at least for now).

But, you are right - if people don't use them correctly, don't follow the label directions, they can have problems. That's why there are pest control operator's like yourself....who know how to handle the products.

Insecticides dusts can be used as directed in wall voids - it is difficult for homeowners to find dust products labeled for this use. Homeowners can use boric acid dusts...safely as long as they follow the label.

The goal of a carpenter ant treatment should always be finding the colony and taking care of the moisture problem. If you expose the nest, correct the moisture problem, replace the damaged wood - you may not even need insecticides - or limit your use of insecticides.

Homeowners need to know that exterior treatments around foundations/baseboards are not effective. Spraying the roof is not effective. Spraying trees with insecticides is not effective. Contracting for monthly treatments are expensive and not recommended.

Even if you use a bait - the baits don't fix the damaged wood/conditions that made it possible for the ants to take advantage of a structure. So as a PCO, it is helpful to have you identify the colony location/damage to structure and recommend structural repairs.

You are very fortunate to have a low callback rate for carpenter ants no matter what product you use.